Field of the Invention
The present invention relates to thermometers, particularly to thermometers for taking the body temperature of a human patient, and specifically to a clinical thermometer with an optical configuration permitting the patient's temperature to be taken from different distances without contacting the patient with the thermometer.
Description of the Prior Art
There are a variety of known clinical infrared (IR) thermometers. However, most known IR thermometers require that the thermometer contact the patient's skin to take a temperature measurement. This requirement frequently compromises the thermometer's accuracy, because when the thermometer's reading tip touches the skin, the thermometer (if not pre-warmed) cools the skin at the measurement area. Additionally, the relatively warmer skin often heats the thermometer tip, causing further readings to be higher, (especially if the tip is in the field of view of the IR detector). Furthermore, because the thermometer touches the patient's skin, it is imperative that a hygienic protection be provided, such as placing a disposable hygienic cover over the tip or any other portion of the thermometer that may come into physical contact with the patient.
It is known to have a detector assembly with optics, for measuring radiation from an area, with no change of the measured area size and power measured within the predetermined distance limitation. Known devices, however, require a uniform emission (radiance) from across the measured area. This uniform radiance requirement substantially compromises the accurate utility of the device in most practical settings.
Against the foregoing background, the current invention was developed to address the identified problems.